A widespread methodology for performance analysis in the field of communication systems engineering is network simulation. While ns-2 has established itself as virtually the standard network simulation tool, other network simulators have gained more and more attention during the last years. In this paper, we briefly survey new developments in the field of network simulation and conduct a performance comparison study by implementing an identical simulation set-up in five simulators, namely ns-2, OMNet++, ns-3, SimPy and JiST/SWANS. Our results reveal large differences according to both run-time performance and memory usage.